As I see people strenuously doing crunches and sit-ups at the gym, alone and with trainers, here is the case made by Harvard Medical School’s Focus on Fitness e-newsletter: yoga planks are good for core fitness, sit-ups and crunches are not good for the back.

A decade ago, sit-ups and grunting crunches were the standard for tight abs and slim waistlines. But research has proven that they are not effective and may actually cause harm. The repeated sit-ups push the curved spine against the floor with pressure causing damage to the compressed discs in the small of the back. Dr. Stuart McGill’s (known for his expertise on the back) work suggests that in some people the crunches may cause herniated discs.

Sit-ups can tug on tight hip flexors that are engaged in the movement–hip flexors are muscles that run from the thighs to the lumbar vertebrae. This results in lower back pain and discomfort.

Abdominal muscles are just a small group of core muscles. So using just a small group means the rest of the muscles are not worked.

Planks do not wear and tear the vertebrae. They also engage many more muscles–on the front, sides, and back. So they strengthen the whole torso, not just the abs.

The BBC article states: “Research published in 2005 on soldiers stationed at the US military’s Fort Bragg attributed 56% of all the injuries sustained during the two-yearly Army Physical Fitness Test to sit-ups.”

One study suggests that it is not the wear and tear on the discs but genetics that predispose some people to back injury more than others.

Readers may also want to look at a previous post on this blog from November 7, 2011:

As yoga related injuries are rising, can yoga classes hurt your back is a relevant question to ask. You are invited to share positive and not-so-positive experiences so we can all learn from each other.

“I have a lumbar disc that bulged in my early twenties and I’ve been along to classes where the first few poses were all quite strong forward bends. Even trying to good-naturedly to go along with the teacher by bending my knees in these asana would still result in quite a lot of pain later….I have learned to ‘do my own thing’ in a class if I believe the sequence is not appropriate for my body, and to even do my own mini-yoga practice to prepare my back immediately before a class with some teachers.”

She addresses and challenges a common belief that it is important to have a flexible lower back and hamstrings, or strong abdominal and lumbar muscles. That may be a cause of many back injuries. Alison states that endurance and coordination my be better than the strength of the lower back to prevent back injuries. She cites the work of Dr. Stuart McGill, a well-known back expert and professor of spine biomechanics in Canada, who remains largely unknown in the yoga world (at least in the US).

There is so much thoughtful, insightful, and well-researched information in these blog posts that I strongly suggest reading them. There is no sense in repeating all the asanas and possible modifications she describes.

Alison’s writing highlights the importance of a knowledgeable instructor, who is willing to learn, and has the time and intellectual curiosity to read/research. Such teachers are rare. Scientific thinking and background is very helpful. It helps distinguish proper yoga from whatever is out there. So spend some time reading the posts carefully as they are not little sound bites.

Our own personal experience with our bodies, and observing those of our students, makes us realize that much that has been synthesized into yoga was problematic to begin with. For example, most people who come to me from Pilates come with incredibly stiff and painful backs that they did not have before Pilates. Now we have Yogalates! It could be that some are practicing incorrectly. It is also clear that many instructors are poorly trained and intellectually not curious, not willing to think independently. They are given a formulaic set of asanas to work with in group settings.

Another example is the integration of some ballet movements. These movements caused injuries in ballet dancers who turned to yoga for treatment. And some schools of yoga absorbed and integrated those ballet movements (the way hips and knees are turned out) that caused injuries!

Sometimes, erroneously, pain and injury are a badge of honor, effort, and commitment to “yoga.” There is also the student’s unrealistic expectation of performing gymnastics as that is the perception of yoga asana. Some teachers measure their own worth by how much they can push the students into performing the most challenging asanas which may be totally inappropriate.

As always, this blog suggests going to the great masters of yoga such as Iyengar and Swami Satyananda who address issues on yoga therapy intelligently. Read their books carefully–Light on Yoga and Asana Pranayama Mudra Bandha.